The present invention relates to a mechanism of elastic prop for reclining portions of office chairs and the like.
As is known, office chairs generally have portions with adjustable height and/or inclination.
In particular, they can be adjusted in the inclination of the back, and sometimes of the seat as well.
In the latter case the seat can be wholly integral with the back, so that both can incline together of the same angle, or the seat can be only partially connected with the back so as to incline less than the latter.
Chairs of the above-mentioned kind should normally be provided with mechanisms of elastic prop for reclining portions, which can exert on said portions reaction forces opposed to those developed against said portions by the user""s body.
Moreover, said chairs usually consist of a primary body, for instance box-shaped, adapted to be engaged with an upper end of an upright defining a vertical stand for an office chair.
A support element of the back is turnably engaged with the primary body around an oscillation axis, so as to enable the adjustment of the inclination of said back. At least a support element of the seat of the chair is located above the primary body.
The mechanism of elastic prop is generally placed between said primary body and said support element and comprises at least an elastic element with linear strain, such as for instance a cylindrical helical compression spring, having a main direction of development which is perpendicular to the oscillation axis of said support element and a first end which abuts against the primary body.
Moreover, the mechanism of elastic prop comprises means to transfer to the elastic element the pressing force pushing the back backwards, said means being placed between the support element and a second end of said elastic element.
In practice, in the known technique said transfer means normally consist of a part of the above-mentioned support element arranged outside said second end of the elastic element, so as to abut against said second end.
The known technique, briefly disclosed above, is disadvantageous because it makes it necessary to place the elastic element in a given position, for instance in a position close to the front edge of the chair, since the above-mentioned second end of said elastic element should not be placed in such an inner position to be in contact with the pushing portion of the support element.
In practice, the primary body of the chair does not often have a suitable front space which can house the group for the adjustment of the elastic force of the elastic element with linear strain and which can be easily handled from outside.
In some technical applications the length of the elastic element and the need to compress it on its ends makes it necessary to place it in an inclined, almost vertical position, thus giving rise to quite bulky and high primary bodies of the chair.
In this situation the technical task of the present invention is to provide for a reclining device for chairs and a chair with said reclining device which can substantially obviate said disadvantages.
Within said technical task an important purpose of the present invention is to provide for a reclining device for chairs and a chair with said reclining device which enables the maximum freedom in the design of a wide range of technical solutions, allowing for instance to place the elastic element horizontally and/or in a withdrawn position with respect to the front edge of the seat or anyway in the position which is deemed as most suitable from a functional point of view, also considering the chair comfort and the easy handling of its adjustments.
A final technical purpose of the present invention is to provide for a reclining device for chairs and a chair with said reclining device which can be easily carried out with limited costs.
The technical task and the purposes indicated above are substantially reached by a reclining device for chairs and a chair with said reclining device comprising one or more of the technical solutions claimed later.